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24P System - 60i vs. 24PsF on EX1R

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Bob Cole
24P System - 60i vs. 24PsF on EX1R
on Oct 14, 2011 at 12:33:14 am

In the Camera Menu/Video Set, there is an option which applies when you are shooting HQ1920/24P or HQ1440/24P.

You can select a "video output format" of either 60i or 24PsF.

Could someone please explain the significance of this? Does it affect only the monitoring of the image from the camera, or is it baked into the video itself?

Thoroughly confused,

Bob C


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john sharaf
Re: 24P System - 60i vs. 24PsF on EX1R
on Oct 14, 2011 at 12:46:26 am

Controls video out spigot which you could use for monitoring and/or recording on connected device, essentially recording 24p internally and applying the 3:2 telecine pull down on the output. One use would be to feed an uplink with a film look, another to provide a smoother ( flicker free) picture to a CRT monitor, etc.

JS


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Bob Cole
Re: 24P System - 60i vs. 24PsF on EX1R
on Oct 14, 2011 at 1:04:14 am

Thank you John. I don't understand 24PsF, despite having just read the Wikipedia article on it. But as long as I don't have trouble monitoring the 24P image on my monitor, and as long as I'm not recording to an external device, can I just ignore this setting? I've left it at the default, which is 60i.

Bob C


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john sharaf
Re: 24P System - 60i vs. 24PsF on EX1R
on Oct 14, 2011 at 1:09:00 am

Yes. 24p was primarily designed to both make video camera motion the same as film camera motion (of course a 180 degree shutter must be invoked as well). In addition it facilitates film out as a frame for frame process.

JS


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Neil Sadwelkar
Re: 24P System - 60i vs. 24PsF on EX1R
on Oct 21, 2011 at 6:19:51 pm

Not sure if this is the right forum as this question is about the F3.

I needed to advice someone wanting to shoot at exactly 24fps (not 23.98) from the F3 on to a KiPro*
But even in 'NTSC mode' the F3 cannot record or output 24fps as far as we could tell, from the menus.

Further, over HDMI the F3 cannot output 1080p23.98 or 1080psf23.98 without adding a pull down to 29.97. Because, apparently, HDMI cannot convey psf23.98. So the KiPro records a clip as 1080p29.97 or that's how it appears to FCP.

HD-SDI out of the SDI port on the F3 does output 1080p.23.98 which the KiPro records correctly as 1080p23.98 and FCP too sees a 23.98 clip.

So is there any way at all, to actually shoot at exactly 24fps with a F3 camera and output a 24p signal out the HDMI or HDSDI? Even if there was, can the KiPro actually record exactly 24fps, or 24p or 24psf. I think not.

*exactly 24fps, because in PAL countries, we have no use for 23.98. And because of the severe pitch and tempo shift, shooting at 25fps and then slowing everything down by 4% to 24fps is not an elegant option.

-----------------------------------
Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India


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Don Greening
Re: 24P System - 60i vs. 24PsF on EX1R
on Oct 14, 2011 at 4:41:24 am

[Bob Cole] "I don't understand 24PsF, despite having just read the Wikipedia article on it."

PsF appeared in the early 1990's as a way to easily share video between broadcasters. Sony (and others) still uses it because broadcasters want to get as much use out of their aging interlacing gear as possible and the camera makers make most of their money by selling to broadcasters.

PsF (progressive segmented frame) splits the progressive frame into odd and even lines to fit the interlacing signal. True interlacing has 60 partial frames a second and each of those frames shows a completely different point in time, along with the motion associated with it. 30 frame PsF uses the same format and the progressive frame is split into odd and even lines to fill 2 interlacing frames but there is only a frame change (and therefore motion change) every 30th of a second. At the other end of the pipe what emerges is a re-assembled true progressive frame. 24p can still be recorded as PsF with the addition of pull-down.

PsF exists solely to add more life to legacy interlaced gear.

- Don

Don Greening
A Vancouver Video Production Company
Reeltime Videoworks
http://www.reeltimevideoworks.com


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